Electric vehicles, such as hybrid vehicles or range extender vehicles, include one or more electric motors configured to drive a ground engaging mechanism of the vehicle. Electric vehicles typically include a generator driven by a prime mover, such as an engine, for generating electrical power used to drive the motor of the vehicle.
In some systems, electrical power from the generator is rectified and stored on a direct current (DC) bus for powering one or more loads on the vehicle, such as the electric motor. In some electric vehicles, the engine output is coupled to the generator such that the generator rotates as the engine rotates, including when the engine is idling. In these vehicles, the engine is shut down to stop rotation and power generation of the generator. The engine is often used to power other vehicle components, such as a hydraulic steering system and other vehicle hydraulics, for example. As such, keeping the engine running when the vehicle is stopped facilitates operation of the hydraulics and the vehicle controllers powered by the generator.
Generator system components occasionally fail for various reasons. One type of failure is a phase-to-phase fault, which may include the presence of a short circuit between phases of the generator output. Continued generation of power by the generator when there is a phase-to-phase fault may create a safety hazard, such as, for example, overheating of the generator components and the DC bus.
According to an embodiment of the present disclosure, an electric vehicle is provided that includes a chassis, a ground engaging mechanism configured to support the chassis, an engine, and a generator driven by the engine. The generator is configured to generate electrical energy and to provide the electrical energy on a multi-phase output. The vehicle further includes a DC bus configured to receive electrical energy provided from the generator and a sensor configured to detect an energy level on the DC bus. The vehicle further includes a controller configured to control routing of electrical energy from the multi-phase output to the DC bus. The controller is configured to monitor the energy level on the DC bus based on the sensor. The controller includes fault management logic operative to determine the presence of a fault between phases of the multi-phase output based on a comparison of the energy level on the DC bus to a threshold energy level.
According to another embodiment of the present disclosure, a fault detection method is provided for a vehicle having an engine-driven generator. The method includes providing a vehicle having a chassis, an engine, a generator driven by the engine, and a DC bus. The generator is configured to provide electrical energy on a multi-phase output. The method includes routing electrical energy from the multi-phase output to the DC bus and monitoring an energy level of the DC bus. The method further includes determining the presence of a fault between phases of the multi-phase output based on the energy level of the DC bus. In one example, the monitoring of the energy level includes monitoring the voltage level on the DC bus, and the determining is based on a comparison of the voltage level on the DC bus to a threshold voltage level.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate exemplary embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.